Fleas have remarkable jumping ability. A 0.50 mg flea, jumping straight up, would reach a height of $40 \mathrm{cm}$ if there were no air resistance. In reality, air resistance limits the height
to $20 \mathrm{cm}$
a. What is the flea's kinetic energy as it leaves the ground?
b. At its highest point, what fraction of the initial kinetic energy has been converted to potential energy?